Abstract The fast reactor code system SARAX, which was developed at Xi’an Jiaotong University, has recently been extended for wider energy range in order to meet the requirements of new reactor designs with intermediate spectrum. The extension efforts mainly included three parts. First, the new pointwise and multigroup cross-section libraries considering the thermal scattering law were generated by the Atlas code and GESALIB interface. Second, the energy-partitioned resonance self-shielding treatment was used to consider the distinct resonance phenomena in the fast and intermediate energy range. The one-dimensional hyperfine group method was integrated for wide resonance self-shielding in the intermediate energy range, while the Tone’s method with narrow resonance approximation was used for resonance self-shielding in the fast energy range. Third, the pointwise energy-collapsing super-homogenization technique was proposed to obtain the reaction rate conservation in the pointwise-multigroup equivalence. The new SARAX system was verified against several problems with different neutron-moderating materials. Results showed that for the heterogeneous subassembly calculation, the eigenvalue error was less than 100 pcm, and the relative error of multigroup self-shielded cross-sections of major actinides was less than 3.1% compared to the results of Monte-Carlo code OpenMC. For the lead-cooled small modular reactor with beryllium reflector, the results of eigenvalue, Doppler constant, power distribution all agreed well with the OpenMC results.

中文翻译：

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中谱反应堆的SARAX编码系统扩展

摘要 西安交通大学开发的快堆编码系统SARAX，最近扩展到了更宽的能量范围，以满足新型中谱反应堆设计的要求。推广工作主要包括三个部分。首先，考虑热散射定律的新的逐点和多组横截面库是由 Atlas 代码和 GESALIB 接口生成的。其次，能量分配共振自屏蔽处理用于考虑快和中能量范围内的明显共振现象。一维超精细群法被集成用于中能量范围内的宽共振自屏蔽，而具有窄共振近似的Tone方法用于快能范围内的共振自屏蔽。第三，提出了逐点能量坍缩超均化技术来获得逐点多群等价的反应速率守恒。新的 SARAX 系统已针对不同中子减速材料的几个问题进行了验证。结果表明，与蒙特卡罗代码OpenMC的结果相比，异构子组件计算的特征值误差小于100 pcm，主锕系元素多组自屏蔽截面的相对误差小于3.1%。对于带铍反射器的铅冷小型模块化反应堆，特征值、多普勒常数、功率分布等结果与OpenMC结果吻合较好。新的 SARAX 系统已针对不同中子减速材料的几个问题进行了验证。结果表明，与蒙特卡罗代码OpenMC的结果相比，异构子组件计算的特征值误差小于100 pcm，主锕系元素多组自屏蔽截面的相对误差小于3.1%。对于带铍反射器的铅冷小型模块化反应堆，特征值、多普勒常数、功率分布等结果与OpenMC结果吻合较好。新的 SARAX 系统已针对不同中子减速材料的几个问题进行了验证。结果表明，与蒙特卡罗代码OpenMC的结果相比，异构子组件计算的特征值误差小于100 pcm，主锕系元素多组自屏蔽截面的相对误差小于3.1%。对于带铍反射器的铅冷小型模块化反应堆，特征值、多普勒常数、功率分布等结果与OpenMC结果吻合较好。1% 与蒙特卡罗代码 OpenMC 的结果相比。对于带铍反射器的铅冷小型模块化反应堆，特征值、多普勒常数、功率分布等结果与OpenMC结果吻合较好。1% 与蒙特卡罗代码 OpenMC 的结果相比。对于带铍反射器的铅冷小型模块化反应堆，特征值、多普勒常数、功率分布等结果与OpenMC结果吻合较好。